Juggling weighty issues of global diplomacy on a whistlestop tour of eastern Europe with tricky decisions about flower arrangements is not the average dilemma for one of the world's most powerful politicians.

But the US secretary of state, Hillary Clinton, admitted to Polish television today that her paramount preoccupation at present is not missile defence or good governance in the former Soviet bloc but preparations for the forthcoming nuptials of her 30-year-old daughter, Chelsea, who is tipped to be married at the end of the month at a mansion in upstate New York. "It truly is the most important thing in my life right now," said Clinton, taking time out from dispensing independence day greetings to US consulate staff in Krakow.

"Luckily, we have email now. I can communicate and people can send me pictures of flower arrangements and other kinds of decisions."

Washington has been buzzing with rumours about wedding plans since the Clintons' only daughter got engaged in November to a childhood friend, Goldman Sachs banker Marc Mezvinsky. US newspaper reports this weekend suggested the ceremony will take place on 31 July at the Astor Courts, a sprawling beaux-arts pavilion in the small town of Rhinebeck, 100 miles north of New York City.

Chelsea has been an object of fascination since her teenage years in the White House, when she was obliged to endure her parents' all-too-public marital difficulties in the fallout from Bill Clinton's affair with Oval Office intern Monica Lewinsky. Initially determinedly low-profile, Chelsea adopted a public role in the 2008 presidential election, standing in for her mother at campaign stops. Now a graduate student at Columbia University, her wedding will be an interfaith affair – the Clintons are Baptists, while Mezvinsky is Jewish.

Bill Clinton joked recently that his daughter had instructed him to lose 7kg (15lb) in order to look good while walking her down the aisle. And Hillary Clinton made clear she is fully involved – despite a tight schedule on a five-day trip taking in Ukraine, Poland, Azerbaijan, Armenia and Georgia, she said she had "been able to fit in tastings and dress selections and all the other things a mother of the bride has to do".

The marriage will add colourful in-laws to the Clinton clan. Mezvinsky's parents are former Democratic members of Congress. The groom's father, Ed Mezvinsky, has had a tricky time since leaving office. He was released from prison in 2008 after a five-year sentence for fraud.

There has been speculation that Barack Obama may attend the wedding. But one Clinton-era couple will be absent – Al Gore and his wife, Tipper, released a statement wishing Chelsea well but saying they would not be attending. The pair recently separated and Al Gore is facing a police investigation over allegations that he sexually assaulted a masseuse.